Allocation and balancing of storage resources

ABSTRACT

A method and technique for allocation and balancing of storage resources includes monitoring, for each of a plurality of storage controllers, an input/output (I/O) latency value based on an I/O latency associated with each storage volume controlled by a respective storage controller. A network bandwidth utilization value and a network latency value corresponding to each storage controller is also monitored. An I/O latency value threshold, a network bandwidth utilization threshold, and a network latency value threshold is determined. Responsive to at least one of the I/O latency value, the network bandwidth utilization value and the network latency value for at least one storage controller exceeding a respective threshold, storage volume distribution among the storage controllers is rebalanced.

BACKGROUND

In cloud and other types of computing systems, a customer or user mayrequest that a storage volume be allocated so it may be used by one ormore virtual machines (i.e., a virtualized allocation of shared computerresources). For example, in response to a request to allocate a storagevolume, cloud computing systems may locate a storage controller withsufficient space from which to allocate the new storage volume.

BRIEF SUMMARY

According to one aspect of the present disclosure a method and techniquefor allocating and balancing storage resources is disclosed. The methodincludes monitoring, for each of a plurality of storage controllers, aninput/output (I/O) latency value based on an I/O latency associated witheach storage volume controlled by a respective storage controller. Anetwork bandwidth utilization value and a network latency valuecorresponding to each storage controller is also monitored. An I/Olatency value threshold, a network bandwidth utilization threshold, anda network latency value threshold is determined. Responsive to at leastone of the I/O latency value, the network bandwidth utilization valueand the network latency value for at least one storage controllerexceeding a respective threshold, storage volume distribution among thestorage controllers is rebalanced.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

For a more complete understanding of the present application, theobjects and advantages thereof, reference is now made to the followingdescriptions taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 depicts a cloud computing node according to an embodiment of thepresent invention;

FIG. 2 depicts a cloud computing environment according to an embodimentof the present invention;

FIG. 3 depicts abstraction model layers according to an embodiment ofthe present invention;

FIG. 4 depicts an embodiment of a data processing system in whichillustrative embodiments of a system for allocating and balancingstorage resources may be implemented;

FIG. 5 depicts a flow diagram illustrating an embodiment of a method forallocating and balancing storage resources;

FIG. 6 depicts a flow diagram illustrating another embodiment of amethod for allocating and balancing storage resources; and

FIG. 7 depicts a flow diagram illustrating another embodiment of amethod for allocating and balancing storage resources.

DETAILED DESCRIPTION

Embodiments of the present disclosure provide a method, system andcomputer program product for allocating and balancing storage resources.For example, in some embodiments, the method and technique includes:determining, for each of a plurality of storage controllers, aninput/output (I/O) latency value based on an I/O latency associated witheach storage volume controlled by a respective storage controller;determining a network bandwidth utilization value and a network latencyvalue corresponding to each storage controller; responsive to receivinga request to allocate a new storage volume, selecting a storagecontroller having a desired I/O latency value; determining whether thenetwork bandwidth utilization value and the network latency value forthe selected storage controller are below a respective network bandwidthutilization threshold and a network latency value threshold; andresponsive to determining that the network bandwidth utilization valueand the network latency value for the selected storage controller arebelow the respective network bandwidth utilization threshold and networklatency value threshold, allocating the new storage volume to theselected storage controller. Thus, embodiments of the present disclosureenable efficient management of storage resources by monitoring andmanaging storage pool resources to maximize and/or otherwise maintaindesired performance levels associated with operation response times. Forexample, embodiments of the present disclosure monitor I/O latency,network latency and network bandwidth utilization to determine storagevolume placement and allocation. Further, embodiments of the presentdisclosure monitor I/O latency, network latency and network bandwidthutilization to determine whether storage volumes should be re-allocatedand/or rebalanced among system storage controllers to reduce and/orminimize I/O latency, network latency and/or network bandwidthutilization for storage resources. Embodiments of the present disclosuremay also monitor and/or analyze network resources (e.g., a quantity ofnetwork hops via switches, routers and/or other data transition points)to improve and/or maximize storage performance.

As will be appreciated by one skilled in the art, aspects of the presentdisclosure may be embodied as a system, method or computer programproduct. Accordingly, aspects of the present disclosure may take theform of an entirely hardware embodiment, an entirely software embodiment(including firmware, resident software, micro-code, etc.) or anembodiment combining software and hardware aspects that may allgenerally be referred to herein as a “circuit,” “module” or “system.”Furthermore, aspects of the present disclosure may take the form of acomputer program product embodied in one or more computer readablemedium(s) having computer readable program code embodied thereon.

Any combination of one or more computer usable or computer readablemedium(s) may be utilized. The computer readable medium may be acomputer readable signal medium or a computer readable storage medium. Acomputer readable storage medium may be, for example but not limited to,an electronic, magnetic, optical, electromagnetic, infrared, orsemiconductor system, apparatus, or device, or any suitable combinationof the foregoing. More specific examples (a non-exhaustive list) of thecomputer readable storage medium would include the following: anelectrical connection having one or more wires, a portable computerdiskette, a hard disk, a random access memory (RAM), a read-only memory(ROM), an erasable programmable read-only memory (EPROM or Flashmemory), an optical fiber, a portable compact disc read-only memory(CD-ROM), an optical storage device, a magnetic storage device, or anysuitable combination of the foregoing. In the context of this document,a computer readable storage medium may be any tangible medium that cancontain, or store a program for use by or in connection with andinstruction execution system, apparatus or device.

A computer readable signal medium may include a propagated data signalwith computer readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including, but not limited to,electro-magnetic, optical, or any suitable combination thereof. Acomputer readable signal medium may be any computer readable medium thatis not a computer readable storage medium and that can communicate,propagate, or transport a program for use by or in connection with aninstruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmittedusing any appropriate medium, including but not limited to wireless,wireline, optical fiber cable, RF, etc., or any suitable combination ofthe foregoing.

Computer program code for carrying out operations for aspects of thepresent disclosure may be written in any combination of one or moreprogramming languages, including an object oriented programming languagesuch as Java, Smalltalk, C++ or the like and conventional proceduralprogramming languages, such as the “C” programming language or similarprogramming languages. The program code may execute entirely on theuser's computer, partly on the user's computer, as a stand-alonesoftware package, partly on the user's computer and partly on a remotecomputer or entirely on the remote computer or server. In the latterscenario, the remote computer may be connected to the user's computerthrough any type of network, including a local area network (LAN) or awide area network (WAN), or the connection may be made to an externalcomputer (for example, through the Internet using an Internet ServiceProvider).

Aspects of the present disclosure is described below with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems) and computer program products according to embodiments of thedisclosure. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer program instructions. These computer program instructions maybe provided to a processor of a general purpose computer, specialpurpose computer, or other programmable data processing apparatus toproduce a machine, such that the instructions, which execute via theprocessor of the computer or other programmable data processingapparatus, create means for implementing the functions/acts specified inthe flowchart and/or block diagram block or blocks.

These computer program instructions may also be stored in acomputer-readable medium that can direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer-readablemedium produce an article of manufacture including instruction meanswhich implement the function/act specified in the flowchart and/or blockdiagram block or blocks.

The computer program instructions may also be loaded onto a computer orother programmable data processing apparatus to cause a series ofoperational steps to be performed on the computer or other programmableapparatus to produce a computer implemented process such that theinstructions which execute on the computer or other programmableapparatus provide processes for implementing the functions/actsspecified in the flowchart and/or block diagram block or blocks.

It is understood in advance that although this disclosure includes adetailed description on cloud computing, implementation of the teachingsrecited herein are not limited to a cloud computing environment. Rather,embodiments of the present invention are capable of being implemented inconjunction with any other type of computing environment now known orlater developed.

Cloud computing is a model of service delivery for enabling convenient,on-demand network access to a shared pool of configurable computingresources (e.g. networks, network bandwidth, servers, processing,memory, storage, applications, virtual machines, and services) that canbe rapidly provisioned and released with minimal management effort orinteraction with a provider of the service. This cloud model may includeat least five characteristics, at least three service models, and atleast four deployment models.

Characteristics are as follows:

On-demand self-service: a cloud consumer can unilaterally provisioncomputing capabilities, such as server time and network storage, asneeded automatically without requiring human interaction with theservice's provider.

Broad network access: capabilities are available over a network andaccessed through standard mechanisms that promote use by heterogeneousthin or thick client platforms (e.g., mobile phones, laptops, and PDAs).

Resource pooling: the provider's computing resources are pooled to servemultiple consumers using a multi-tenant model, with different physicaland virtual resources dynamically assigned and reassigned according todemand. There is a sense of location independence in that the consumergenerally has no control or knowledge over the exact location of theprovided resources but may be able to specify location at a higher levelof abstraction (e.g., country, state, or datacenter).

Rapid elasticity: capabilities can be rapidly and elasticallyprovisioned, in some cases automatically, to quickly scale out andrapidly released to quickly scale in. To the consumer, the capabilitiesavailable for provisioning often appear to be unlimited and can bepurchased in any quantity at any time.

Measured service: cloud systems automatically control and optimizeresource use by leveraging a metering capability at some level ofabstraction appropriate to the type of service (e.g., storage,processing, bandwidth, and active user accounts). Resource usage can bemonitored, controlled, and reported providing transparency for both theprovider and consumer of the utilized service.

Service Models are as follows:

Software as a Service (SaaS): the capability provided to the consumer isto use the provider's applications running on a cloud infrastructure.The applications are accessible from various client devices through athin client interface such as a web browser (e.g., web-based email). Theconsumer does not manage or control the underlying cloud infrastructureincluding network, servers, operating systems, storage, or evenindividual application capabilities, with the possible exception oflimited user-specific application configuration settings.

Platform as a Service (PaaS): the capability provided to the consumer isto deploy onto the cloud infrastructure consumer-created or acquiredapplications created using programming languages and tools supported bythe provider. The consumer does not manage or control the underlyingcloud infrastructure including networks, servers, operating systems, orstorage, but has control over the deployed applications and possiblyapplication hosting environment configurations.

Infrastructure as a Service (IaaS): the capability provided to theconsumer is to provision processing, storage, networks, and otherfundamental computing resources where the consumer is able to deploy andrun arbitrary software, which can include operating systems andapplications. The consumer does not manage or control the underlyingcloud infrastructure but has control over operating systems, storage,deployed applications, and possibly limited control of select networkingcomponents (e.g., host firewalls).

Deployment Models are as follows:

Private cloud: the cloud infrastructure is operated solely for anorganization. It may be managed by the organization or a third party andmay exist on-premises or off-premises.

Community cloud: the cloud infrastructure is shared by severalorganizations and supports a specific community that has shared concerns(e.g., mission, security requirements, policy, and complianceconsiderations). It may be managed by the organizations or a third partyand may exist on-premises or off-premises.

Public cloud: the cloud infrastructure is made available to the generalpublic or a large industry group and is owned by an organization sellingcloud services.

Hybrid cloud: the cloud infrastructure is a composition of two or moreclouds (private, community, or public) that remain unique entities butare bound together by standardized or proprietary technology thatenables data and application portability (e.g., cloud bursting forloadbalancing between clouds).

A cloud computing environment is service oriented with a focus onstatelessness, low coupling, modularity, and semantic interoperability.At the heart of cloud computing is an infrastructure comprising anetwork of interconnected nodes.

Referring now to FIG. 1, a schematic of an example of a cloud computingnode is shown. Cloud computing node 10 is only one example of a suitablecloud computing node and is not intended to suggest any limitation as tothe scope of use or functionality of embodiments of the inventiondescribed herein. Regardless, cloud computing node 10 is capable ofbeing implemented and/or performing any of the functionality set forthhereinabove.

In cloud computing node 10 there is a computer system/server 12, whichis operational with numerous other general purpose or special purposecomputing system environments or configurations. Examples of well-knowncomputing systems, environments, and/or configurations that may besuitable for use with computer system/server 12 include, but are notlimited to, personal computer systems, server computer systems, thinclients, thick clients, handheld or laptop devices, multiprocessorsystems, microprocessor-based systems, set top boxes, programmableconsumer electronics, network PCs, minicomputer systems, mainframecomputer systems, and distributed cloud computing environments thatinclude any of the above systems or devices, and the like.

Computer system/server 12 may be described in the general context ofcomputer system executable instructions, such as program modules, beingexecuted by a computer system. Generally, program modules may includeroutines, programs, objects, components, logic, data structures, and soon that perform particular tasks or implement particular abstract datatypes. Computer system/server 12 may be practiced in distributed cloudcomputing environments where tasks are performed by remote processingdevices that are linked through a communications network. In adistributed cloud computing environment, program modules may be locatedin both local and remote computer system storage media including memorystorage devices.

As shown in FIG. 1, computer system/server 12 in cloud computing node 10is shown in the form of a general-purpose computing device. Thecomponents of computer system/server 12 may include, but are not limitedto, one or more processors or processing units 16, a system memory 28,and a bus 18 that couples various system components including systemmemory 28 to processor 16.

Bus 18 represents one or more of any of several types of bus structures,including a memory bus or memory controller, a peripheral bus, anaccelerated graphics port, and a processor or local bus using any of avariety of bus architectures. By way of example, and not limitation,such architectures include Industry Standard Architecture (ISA) bus,Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, VideoElectronics Standards Association (VESA) local bus, and PeripheralComponent Interconnects (PCI) bus.

Computer system/server 12 typically includes a variety of computersystem readable media. Such media may be any available media that isaccessible by computer system/server 12, and it includes both volatileand non-volatile media, removable and non-removable media.

System memory 28 can include computer system readable media in the formof volatile memory, such as random access memory (RAM) 30 and/or cachememory 32. Computer system/server 12 may further include otherremovable/non-removable, volatile/non-volatile computer system storagemedia. By way of example only, storage system 34 can be provided forreading from and writing to a non-removable, non-volatile magnetic media(not shown and typically called a “hard drive”). Although not shown, amagnetic disk drive for reading from and writing to a removable,non-volatile magnetic disk (e.g., a “floppy disk”), and an optical diskdrive for reading from or writing to a removable, non-volatile opticaldisk such as a CD-ROM, DVD-ROM or other optical media can be provided.In such instances, each can be connected to bus 18 by one or more datamedia interfaces. As will be further depicted and described below,memory 28 may include at least one program product having a set (e.g.,at least one) of program modules that are configured to carry out thefunctions of embodiments of the invention.

Program/utility 40, having a set (at least one) of program modules 42,may be stored in memory 28 by way of example, and not limitation, aswell as an operating system, one or more application programs, otherprogram modules, and program data. Each of the operating system, one ormore application programs, other program modules, and program data orsome combination thereof, may include an implementation of a networkingenvironment. Program modules 42 generally carry out the functions and/ormethodologies of embodiments of the invention as described herein.

Computer system/server 12 may also communicate with one or more externaldevices 14 such as a keyboard, a pointing device, a display 24, etc.;one or more devices that enable a user to interact with computersystem/server 12; and/or any devices (e.g., network card, modem, etc.)that enable computer system/server 12 to communicate with one or moreother computing devices. Such communication can occur via Input/Output(I/O) interfaces 22. Still yet, computer system/server 12 cancommunicate with one or more networks such as a local area network(LAN), a general wide area network (WAN), and/or a public network (e.g.,the Internet) via network adapter 20. As depicted, network adapter 20communicates with the other components of computer system/server 12 viabus 18. It should be understood that although not shown, other hardwareand/or software components could be used in conjunction with computersystem/server 12. Examples, include, but are not limited to: microcode,device drivers, redundant processing units, external disk drive arrays,RAID systems, tape drives, and data archival storage systems, etc.

Referring now to FIG. 2, illustrative cloud computing environment 50 isdepicted. As shown, cloud computing environment 50 comprises one or morecloud computing nodes 10 with which local computing devices used bycloud consumers, such as, for example, personal digital assistant (PDA)or cellular telephone 54A, desktop computer 54B, laptop computer 54C,and/or automobile computer system 54N may communicate. Nodes 10 maycommunicate with one another. They may be grouped (not shown) physicallyor virtually, in one or more networks, such as Private, Community,Public, or Hybrid clouds as described hereinabove, or a combinationthereof. This allows cloud computing environment 50 to offerinfrastructure, platforms and/or software as services for which a cloudconsumer does not need to maintain resources on a local computingdevice. It is understood that the types of computing devices 54A-N shownin FIG. 2 are intended to be illustrative only and that computing nodes10 and cloud computing environment 50 can communicate with any type ofcomputerized device over any type of network and/or network addressableconnection (e.g., using a web browser).

Referring now to FIG. 3, a set of functional abstraction layers providedby cloud computing environment 50 (FIG. 2) is shown. It should beunderstood in advance that the components, layers, and functions shownin FIG. 3 are intended to be illustrative only and embodiments of theinvention are not limited thereto. As depicted, the following layers andcorresponding functions are provided:

Hardware and software layer 60 includes hardware and softwarecomponents. Examples of hardware components include mainframes, in oneexample IBM® zSeries® systems; RISC (Reduced Instruction Set Computer)architecture based servers, in one example IBM pSeries® systems; IBMxSeries® systems; IBM BladeCenter® systems; storage devices; networksand networking components. Examples of software components includenetwork application server software, in one example IBM Web Sphere®application server software; and database software, in one example IBMDB2® database software. (IBM, zSeries, pSeries, xSeries, BladeCenter,WebSphere, and DB2 are trademarks of International Business MachinesCorporation registered in many jurisdictions worldwide).

Virtualization layer 62 provides an abstraction layer from which thefollowing examples of virtual entities may be provided: virtualmachines, including virtual servers; virtual storage; virtual networks,including virtual private networks; virtual applications and operatingsystems; and virtual clients.

In one example, management layer 64 may provide the functions describedbelow. Resource provisioning provides dynamic procurement of computingresources and other resources that are utilized to perform tasks withinthe cloud computing environment. Metering and Pricing provide costtracking as resources are utilized within the cloud computingenvironment, and billing or invoicing for consumption of theseresources. In one example, these resources may comprise applicationsoftware licenses. Security provides identity verification for cloudconsumers and tasks, as well as protection for data and other resources.User portal provides access to the cloud computing environment forconsumers and system administrators. Service level management providescloud computing resource allocation and management such that requiredservice levels are met. Service Level Agreement (SLA) planning andfulfillment provide pre-arrangement for, and procurement of, cloudcomputing resources for which a future requirement is anticipated inaccordance with an SLA. Service level management may also includevirtual machine allocation and management such that the migration and/orexecution of virtual machine resources (e.g., various workload orapplication processing) complies with the geophysical host location.

Workloads layer 66 provides examples of functionality for which thecloud computing environment may be utilized. Examples of workloads andfunctions which may be provided from this layer include: mapping andnavigation; software development and lifecycle management; virtualclassroom education delivery; data analytics processing; transactionprocessing; and mobile desktop functions.

FIG. 4 is an illustrative embodiment of a system 400 for storagemanagement in a cloud or other type of computing environment. System 400may be implemented on data processing systems or platforms such as, butnot limited to, node 10 or at other data processing system locations.System 400 (e.g., all or portions thereof) may be implemented, forexample, on hardware and software layer 60 and/or on management layer 64as depicted in FIG. 3. In the embodiment illustrated in FIG. 4, system400 comprises a host 402 comprising a physical computer or any type ofdata processing platform. Host 402 includes one or more processor units404 (e.g., CPU) capable of reading and executing instructions and/orrunning a variety of types of applications and a memory 406. In FIG. 4,memory comprises a hypervisor or virtualization module 410 for logicallydividing and/or virtualizing various resources of host 402 (e.g.,sharing of memory 406 and/or processor units 404). Virtualization module410 generally comprises a low-level application that supports allocationand/or execution of one or more virtual machines 412 (e.g., virtualmachines (VMs) 412 ₁, 412 ₂ through 412 _(n)). For example,virtualization module 410 may include an allocation manager forallocating and/or logically dividing and virtualizing computer resources(including the allocation and/or sharing of one or more processing unitsand/or memory) to thereby form a platform for each of the respectivevirtual machines 412. Multiple virtual machines 412 may be allocated onhost 402. Each virtual machine 412 may respectively support an instanceof an operating system and one or more applications 414 executable onthe virtual processing device allocated to the respective virtualmachine 412.

In the embodiment illustrated in FIG. 4, memory also comprises a storagemanagement application 420 for managing various storage-relatedfunctions as described herein. Virtualization module 410 and managementapplication 420 may be implemented in any suitable manner that may behardware-based, software-based, or some combination of both. Forexample, virtualization module 410 and management application 420 maycomprise software, logic and/or executable code for performing variousfunctions as described herein (e.g., residing as software and/or analgorithm running on a processor unit, hardware logic residing in aprocessor or other type of logic chip, centralized in a singleintegrated circuit or distributed among different chips in a dataprocessing system). Management application 420 is configured to obtain,analyze and monitor various criteria related to the selection and/ordistribution of storage resources and/or the control of those storageresources. For example, in FIG. 4, system 400 includes storagecontrollers 430 (e.g., storage controllers 430 ₁, 430 ₂ through 412_(n)) connected to host 402 via a network 432. Each storage controller430 may be associated with and/or otherwise manage/control storageresources 440. The storage resources 440 may comprise storage volumes442, 444 and 446 (e.g., corresponding to physical storage devices).

Management application 420 acquires and/or otherwise calculates varioustypes of statistical data corresponding to each storage controller 430to determine placement of new storage volumes and/or thedistribution/rebalancing of storage volumes among storage controllers430. For example, in FIG. 4, memory comprises storage data 450comprising information associated with and/or otherwise related to eachstorage controller 430. In the illustrated embodiment, storage data 450comprises an input/output (I/O) latency value(s) 452, a network latencyvalue(s) 454, and a network bandwidth utilization value(s) 456. I/Olatency value 452 comprises a value representing the latency of storageinput/output operations corresponding to a respective storage controller430. For example, in some embodiments, an average I/O latency value iscalculated by management application 420 based on input/outputoperations corresponding to each storage volume controlled by aparticular storage controller. In this example, management module 420polls a particular storage controller 430 (e.g., storage controller 430₁) to gather I/O statistics corresponding to each storage volume 442managed/controlled by storage controller 430 ₁, such as the average readand write response times for a particular storage volume 442. Managementapplication 420 calculates the average I/O latency for each storagevolume 442, sums the average latencies for the storage volumes 442controlled/managed by storage controller 430 ₁, and divides by thequantity of storage volumes 442 controlled/managed by storage controller430 ₁. Thus, in this manner, an average I/O latency value 452 may becalculated/determined for each storage controller 430 based on thestorage volumes controlled/managed by the respective storage controller430. In some embodiments, management application 420 may weight eachstorage volume by the amount of data being read/written to a respectivestorage volume (e.g., so a storage volume that writes one byte of dataand gets a high latency will not skew the overall latency of therespective storage controller 430). In some embodiments, the I/O latencyvalue may comprise and/or be based on a weighted average of I/O responsetimes. For example, in some embodiments, write operations may beweighted greater than read operations, or vice versa (e.g., writeoperations weighted at 70% and read operations weighted at 30%).Further, in some embodiments, the quantity or rate of I/O operations maybe weighted (e.g., a storage volume with a significant quantity or rateof I/O operations given more weight than a storage volume with lowquantity or rate of I/O operations). The weighting may be configurable(e.g., by a user of system 400) to obtain desired statisticalinformation corresponding to I/O operations.

Network latency value 454 comprises a value representing an operationresponse time based on network characteristics corresponding to arespective storage controller 430. For example, in some embodiments,management application 420 polls network resources and/or otherwiseacquires various statistical information corresponding to networkdevices (e.g., switches, links, relays, I/O adapters, etc.)corresponding to a network utilized by and/or otherwise associated withoperations performed by a respective storage controller 430. Networkbandwidth utilization value 456 comprises a value representing thebandwidth utilization otherwise associated with operations performed bya respective storage controller 430.

In operation, management application 420 monitors and/or calculates theI/O latency value 452, network latency value 454 and the networkbandwidth utilization value 456 for each storage controller 430. Inresponse to a request to allocate a new storage volume in system 400(e.g., by a virtual machine 412 and/or other resource, managementapplication 420 determines where to allocate the new storage volume(i.e., to which storage controller 430) to optimize and/or maximizeperformance of storage controllers 430 in system 400. For example, inthe embodiment illustrated in FIG. 4, memory 406 may also include an I/Olatency threshold, 460, a network latency threshold 462 and a networkbandwidth utilization threshold 464 associated with respective I/Olatency value 452, network latency value 454 and network bandwidthutilization value 456. Management application 420 may analyze the I/Olatency value 452, network latency value 454 and network bandwidthutilization value 456 for each storage controller 430 to respective I/Olatency threshold, 460, network latency threshold 462 and networkbandwidth utilization threshold 464 to determine whether a performancedegradation would occur if a storage volume was allocated to aparticular storage controller 430. For example, if the I/O latency value452 for a particular storage controller 430 is near or has exceeded I/Olatency threshold 460, a different storage controller 430 may beselected for the new storage volume. In some embodiments, in response arequest to allocate a new storage volume in system 400, managementapplication 420 may select a particular storage controller 430 with adesired I/O latency value 452 for new storage volume allocation (e.g.,the storage controller 430 with the lowest I/O latency value 452, one ormore storage controllers 430 having an I/O latency value 452 below aparticular threshold, etc.). In some embodiments, afteridentifying/selecting a particular storage volume 430 based on I/Olatency value 452, management application 420 may verify that acorresponding network latency value 454 and network bandwidthutilization value 456 for the identified storage controller 430 are alsobelow the network latency threshold 462 and network bandwidthutilization threshold 464. I/O latency threshold 460, network latencythreshold 462 and network bandwidth utilization threshold 464 may beconfigurable and/or may be defined by a user of system 400. It should beunderstood that in some embodiments, if there is a minimum difference(or amount of difference below some threshold) of I/O latency values 452between two or more storage controllers 430, multiple storagecontrollers 430 may be analyzed (e.g., a particular storage controller430 may not be selected over another storage controller 430 with minimalI/O latency value 452 differences).

In some embodiments, management application 420 may also evaluate and/orconsider a type of application 414 and its use of storage resources indetermining where to allocate a new storage volume and/or rebalancestorage volumes among storage controllers 430. For example, in someembodiments, management application 420 may determine a type ofapplication 414 and it current and/or anticipated storage workload level(e.g., some application 414 may have a light storage workload levelwhere other applications 414 may have higher storage workload demands).Management application 420 may evaluate the type of application 414 thatis or will be utilizing a storage volume to determine where to allocatea new storage volume and/or rebalance current storage volume placementamong storage controllers. In some embodiments, management application420 may also determine, monitor and/or analyze a quantity of networkhops (e.g., via switches, routers and/or other data transition points)between a particular virtual machine 412 and a corresponding storagevolume to determine placement of a new storage volume and/or therebalancing of storage volumes among storage controllers 430 (e.g.,migrating storage volumes to minimize the quantity of network hops).

In some embodiments, management application 420 may also evaluate and/orconsider a priority level associated with a particular application 414and its use of storage resources in determining where to allocate a newstorage volume and/or rebalance storage volumes among storagecontrollers 430. For example, in some embodiments, a user, administratoror other resource may assign and/or otherwise delegate a prioritylevel(s) 466 to different applications 414. Management application 420evaluates priority level 466 corresponding to a particular application414 (e.g., in connection with either allocating a new storage volume orevaluating whether to rebalance storage volumes) to minimize impactand/or maximize performance corresponding to the higher priorityapplications 414. In this embodiment, for example, if one or more of I/Olatency value 452, network latency value 454 and network bandwidthutilization value 456 for a corresponding storage controller 430 (e.g.,storage controller 430 ₁) managing a storage volume associated with thehigh priority level application 414 is nearing and/or has exceeded arespective threshold 460, 462 or 464, management application 420 maycause other storage volumes on the respective storage controller 430 ₁to be migrated to other storage controllers 430 (e.g., storagecontroller 430 ₂) to maximize performance for the higher level priorityapplication 414. Management application 420 may also consider and/orotherwise evaluate the proximity of a particular storage controller 430to a virtual machine 412 that is utilizing a particular storagecontroller 430 to reduce bandwidth utilization and minimize latencies.

As described above, management application 420 may also monitor I/Olatency value 452, network latency value 454 and network bandwidthutilization value 456 for each storage controller 430 and rebalanceand/or redistribute storage volumes among the different storagecontrollers 430 to maximize performance. For example, in response tonetwork failures, increases in storage workloads (e.g., storage and/ornetwork bandwidth usage), re-prioritization of applications 414, etc.,management application 420 may migrate one or more storage volumes fromone storage controller 430 to another storage controller 430.

FIG. 5 is a flow diagram illustrating an embodiment of a method forstorage management. The method begins at block 502, where managementapplication polls storage controllers 430 for storage statisticalinformation. At block 504, management application 420 acquires networkstatistics corresponding to respective storage controllers 430. At block506, management application 420 calculates and/or otherwise determinesI/O latency value 452 for each respective storage controller 430. Atblock 508, management application 420 calculates and/or otherwisedetermines network latency value 454 for each respective storagecontroller 430. At block 510, management application 420 calculatesand/or otherwise determines network bandwidth utilization value 454 foreach respective storage controller 430.

At block 512, a request is received to allocate a new storage volume insystem 400. At block 514, management application 420 selects aparticular storage controller 430 having a desired I/O latency value 452(e.g., one having a lowest I/O latency value 452). At block 516,management application 420 compares network latency value 454 andnetwork bandwidth utilization value 454 for the selected storagecontroller 430 to respective thresholds 462 and 464. At decisional block518, a determination is made whether network latency value 454 andnetwork bandwidth utilization value 454 for the selected storagecontroller 430 are below respective thresholds 462 and 464. If not(e.g., either one or both are not below a respective threshold 462 or464), the method proceeds to block 522, where management application 420selects another storage controller 430 (e.g., one with the next lowestI/O latency value 452). The method then proceeds to block 516. If atdecisional block 518 it is determined that network latency value 454 andnetwork bandwidth utilization value 454 for the selected storagecontroller 430 are below respective thresholds 462 and 464, the methodproceeds to block 520, where management application 420 causes the newstorage volume to be allocated to the selected storage controller 430.In some embodiments, if a selected storage controller 430 does not meetsdesignated criteria for storage volume placement (or if managementapplication 420 is unable to identify a particular storage controller430 that meets designated criteria for storage volume placement),management application 420 may cause a rebalancing of storage volumesamong storage controllers 430 to enable placement of the new storagevolume.

FIG. 6 is a flow diagram illustrating an embodiment of a method forstorage management. The method begins at block 602, where managementapplication polls storage controllers 430 for storage statisticalinformation. At block 604, management application 420 acquires networkstatistics corresponding to respective storage controllers 430. At block606, management application 420 calculates and/or otherwise determinesI/O latency value 452 for each respective storage controller 430. Atblock 608, management application 420 calculates and/or otherwisedetermines network latency value 454 for each respective storagecontroller 430. At block 610, management application 420 calculatesand/or otherwise determines network bandwidth utilization value 454 foreach respective storage controller 430.

At block 612, a request is received to allocate a new storage volume insystem 400. At block 614, management application 420 determines a typeof application 414 that will be utilizing the new storage volume.Management application 420 may also determine the types of applications414 currently utilizing storage resources via previously allocatedstorage volumes. At block 616, management application 420 determines apriority level for application 414 that will be utilizing the newstorage volume. Management application 420 may also determine thepriority levels of applications 414 currently utilizing storageresources via previously allocated storage volumes.

At block 618, management application 420 analyzes I/O latency value 452,network latency value 454 and network bandwidth utilization value 456for respective storage controllers 430. At block 620, managementapplication 420 determines and analyzes the storage workload level basedon the types of applications 414 (e.g., the applications 414 currentlyutilizing storage resources and/or the application 414 that will beutilizing the newly allocated storage volume). At block 622, managementapplication 420 selects a storage controller 430 to allocate a newstorage volume to based on I/O latency values 452, network latencyvalues 454, network bandwidth utilization values 456, the type ofapplications 414 utilizing the storage resources, and the prioritylevels of the various applications 414. For example, managementapplication 420 may be configured to weight certain of theabove-referenced criteria greater than others for selecting a storagecontroller 430. In some embodiments, a greater weight may be placed on apriority level of an application 414 currently utilizing a storageresource such that minimal disruption is desired for its respectivestorage controller 430 (i.e., the newly allocated storage volume beingallocated to a different storage controller 430). In some embodiments,the anticipated workload level corresponding to the new storage volumeto be allocated (e.g., based on the type of application 414 that will beutilizing the storage volume) may result in the unloading of aparticular storage controller 430 (e.g., migrating one or more existingstorage volumes to another storage controller) to facilitate theplacement of the newly allocated storage volume on a desired storagecontroller 430. In some embodiments, management application 420 mayevaluate the proximity of the I/O latency values 452, network latencyvalues 454, and network bandwidth utilization values 456 to respectivethresholds 460, 462 and 464 in connection with an anticipated storageworkload level for the new storage volume to be allocated to determinewhich storage controller 430 should be selected for the new storagevolume and/or whether one or more storage volumes should be migrated toother storage controllers 430 to rebalance or pre-balance (e.g., toachieve a balanced storage controller 430 workload once the new storagevolume is allocated).

FIG. 7 is a flow diagram illustrating another embodiment of a method forstorage resource management. The method begins at block 702, wheremanagement application 420 determines and monitors I/O latency values452, network latency values 454, and network bandwidth utilizationvalues 456 for respective storage controllers 430. At decisional block704, a determination is made whether one or more of I/O latency values452, network latency values 454, and network bandwidth utilizationvalues 456 for a particular storage controller 430 is nearing or hasexceeded a respective threshold 460, 462 or 464. If not, the methodproceeds to block 702 where management application 420 continues tomonitor I/O latency values 452, network latency values 454, and networkbandwidth utilization values 456 for storage controllers 430. If adetermination is made at block 704 that one or more of I/O latencyvalues 452, network latency values 454, and network bandwidthutilization values 456 for a particular storage controller 430 isnearing or has exceeded a respective threshold 460, 462 or 464, themethod proceeds to block 706, where management application 420determines the types of applications 414 utilizing the storage resourcescontrolled by storage controllers 430. At block 708, managementapplication 420 determines storage workload levels for the differenttypes of applications (e.g., based on current use and/or anticipated useof allocated storage volumes). At block 710, management application 420determines a priority level associated with the applications 414utilizing storage volumes. At block 712, management application 420rebalances storage volumes among storage controllers 430 (e.g.,migrating one or more storage volumes from one storage controller 430 toanother storage controller 430). In some embodiments, managementapplication 420 may rebalance storage volume placement among storagecontrollers 430 to maximize performance for applications 414 with higherpriority levels. In some embodiments, management application 420 mayrebalance storage volume placement among storage controllers 430 tocompensate for network failures, high or increasing workload usage ofstorage volumes of a particular storage controller 430, and/or changesin prioritization of certain applications 414. For example, in someembodiments, despite I/O latency values 452, network latency values 454,and network bandwidth utilization values 456 being below respectivethresholds 460, 462 and 464, a change to a priority level of aparticular application 414 may cause storage volumes to be migrated toother storage controllers 430 to ensure that storage resources for theprioritized application 414 are not compromised (e.g., due to a networkfailure or workload level increase).

Thus, embodiments of the present disclosure enable efficient managementof storage resources by monitoring and managing storage pool resourcesto maximize and/or otherwise maintain desired performance levelsassociated with operation response times. For example, embodiments ofthe present disclosure monitor I/O latency, network latency and networkbandwidth utilization to determine storage volume placement andallocation. Further, embodiments of the present disclosure monitor I/Olatency, network latency and network bandwidth utilization to determinewhether storage volumes should be re-allocated and/or rebalanced amongsystem storage controllers to reduce and/or minimize I/O latency,network latency and/or network bandwidth utilization for storageresources.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims below are intended toinclude any structure, material, or act for performing the function incombination with other claimed elements as specifically claimed. Thedescription of the present disclosure has been presented for purposes ofillustration and description, but is not intended to be exhaustive orlimited to the disclosure in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the disclosure. Theembodiment was chosen and described in order to best explain theprinciples of the disclosure and the practical application, and toenable others of ordinary skill in the art to understand the disclosurefor various embodiments with various modifications as are suited to theparticular use contemplated.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof code, which comprises one or more executable instructions forimplementing the specified logical function(s). It should also be notedthat, in some alternative implementations, the functions noted in theblock may occur out of the order noted in the figures. For example, twoblocks shown in succession may, in fact, be executed substantiallyconcurrently, or the blocks may sometimes be executed in the reverseorder, depending upon the functionality involved. It will also be notedthat each block of the block diagrams and/or flowchart illustration, andcombinations of blocks in the block diagrams and/or flowchartillustration, can be implemented by special purpose hardware-basedsystems that perform the specified functions or acts, or combinations ofspecial purpose hardware and computer instructions.

What is claimed is:
 1. A method, comprising: monitoring, for each of aplurality of storage controllers, an input/output (I/O) latency valuebased on an I/O latency associated with each storage volume controlledby a respective storage controller; monitoring a network bandwidthutilization value and a network latency value corresponding to eachstorage controller; determining an I/O latency value threshold, anetwork bandwidth utilization threshold, and a network latency valuethreshold; and responsive to at least one of the I/O latency value, thenetwork bandwidth utilization value and the network latency value for atleast one storage controller exceeding a respective threshold,rebalancing storage volume distribution among the storage controllers.2. The method of claim 1, further comprising calculating the I/O latencyvalue for each storage controller.
 3. The method of claim 2, whereincalculating the I/O latency value for each storage controller includescalculating an average I/O latency value for each storage controller. 4.The method of claim 3, wherein calculating the average I/O latency foreach storage controller comprises: calculating a weighted average I/Olatency value for each storage volume controlled by a respective storagecontroller; summing the weighted I/O latency values of the storagevolumes controlled by the respective storage controller; and dividingthe summed I/O latency values by a quantity of the storage volumescontrolled by the respective storage controller.
 5. The method of claim4, wherein calculating the weighted average I/O latency value for eachstorage volume comprises calculating the weighted average I/O latencyvalue based on weighting write I/O operations greater than read I/Ooperations.
 6. The method of claim 1, further comprising: determining atype of application utilizing one or more of the storage volumes;determining a priority level of the application; and rebalancing thestorage volume distribution among the storage controllers based on thetype of the application and the priority level of the application. 7.The method of claim 1, further comprising: analyzing the I/O latencyvalue, the network bandwidth utilization value and the network latencyvalue for the storage controllers; determining whether moving one ormore storage volumes will lower at least one of the I/O latency value,the network bandwidth utilization value and the network latency valuefor at least one storage controller; and responsive to determining thatmoving one or more storage volumes will lower at least one of the I/Olatency value, the network bandwidth utilization value and the networklatency value for at least one storage controller, migrating at leastone storage volume from one storage controller to another storagecontroller.
 8. A system, comprising: a plurality of storage controllerseach controlling one or more storage volumes; and a processor unitoperable to execute a management application, the management applicationconfigured to: monitor, for each of the plurality of storagecontrollers, an input/output (I/O) latency value based on an I/O latencyassociated with each storage volume controlled by a respective storagecontroller; monitor a network bandwidth utilization value and a networklatency value corresponding to each storage controller; determine an I/Olatency value threshold, a network bandwidth utilization threshold, anda network latency value threshold; and responsive to at least one of theI/O latency value, the network bandwidth utilization value and thenetwork latency value for at least one storage controller exceeding arespective threshold, rebalance storage volume distribution among thestorage controllers.
 9. The system of claim 8, wherein the managementapplication is configured to calculate the I/O latency value for eachstorage controller.
 10. The system of claim 8, wherein the managementapplication is configured to calculate an average I/O latency value foreach storage controller.
 11. The system of claim 10, wherein themanagement application is configured to calculate the average I/Olatency for each storage controller by: calculating a weighted averageI/O latency value for each storage volume controlled by a respectivestorage controller; summing the weighted I/O latency values of thestorage volumes controlled by the respective storage controller; anddividing the summed I/O latency values by a quantity of the storagevolumes controlled by the respective storage controller.
 12. The systemof claim 8, wherein the I/O latency value for each storage controllerincludes a weighted average I/O latency value, wherein the weighting isbased on a rate of I/O operations.
 13. The system of claim 8, whereinthe management application is configured to: determine a type ofapplication utilizing one or more of the storage volumes; determine apriority level of the application; and rebalance the storage volumedistribution among the storage controllers based on the type of theapplication and the priority level of the application.
 14. The system ofclaim 8, wherein the management application is configured to: analyzethe I/O latency value, the network bandwidth utilization value and thenetwork latency value for the storage controllers; determine whethermoving one or more storage volumes will lower at least one of the I/Olatency value, the network bandwidth utilization value and the networklatency value for at least one storage controller; and responsive todetermining that moving one or more storage volumes will lower at leastone of the I/O latency value, the network bandwidth utilization valueand the network latency value for at least one storage controller,migrate at least one storage volume from one storage controller toanother storage controller.
 15. A computer program product for storagemanagement, the computer program product comprising: a computer readablestorage medium having computer readable program code embodied therewith,the computer readable program code comprising computer readable programcode configured to: monitor, for each of a plurality of storagecontrollers, an input/output (I/O) latency value based on an I/O latencyassociated with each storage volume controlled by a respective storagecontroller; monitor a network bandwidth utilization value and a networklatency value corresponding to each storage controller; determine an I/Olatency value threshold, a network bandwidth utilization threshold, anda network latency value threshold; and responsive to at least one of theI/O latency value, the network bandwidth utilization value and thenetwork latency value for at least one storage controller exceeding arespective threshold, rebalance storage volume distribution among thestorage controllers.
 16. The computer program product of claim 15,wherein the computer readable program code is configured to calculatethe I/O latency value for each storage controller.
 17. The computerprogram product of claim 15, wherein the computer readable program codeis configured to calculate an average I/O latency value for each storagecontroller.
 18. The computer program product of claim 17, wherein thecomputer readable program code is configured to calculate the averageI/O latency for each storage controller by: calculating a weightedaverage I/O latency value for each storage volume controlled by arespective storage controller; summing the weighted I/O latency valuesof the storage volumes controlled by the respective storage controller;and dividing the summed I/O latency values by a quantity of the storagevolumes controlled by the respective storage controller.
 19. Thecomputer program product of claim 18, wherein the computer readableprogram code is configured to calculate the weighted average I/O latencyvalue for each storage volume based on weighting a rate of I/Ooperations.
 20. The computer program product of claim 15, wherein thecomputer readable program code is configured to: determine a type ofapplication utilizing one or more of the storage volumes; determine apriority level of the application; and rebalance the storage volumedistribution among the storage controllers based on the type of theapplication and the priority level of the application.